摘 要：为探索枯草芽孢杆菌发酵玉米秸秆产腐植酸的最佳条件。以玉米秸秆与麸皮配比、尿素添加量、培养基初始pH为试验因素，以发酵产物腐植酸含量为指标，根据单因素试验结果选定因素水平，采用Box-Benhnken试验设计法，研究各因素交互作用及其对发酵产腐植酸的影响，拟合获得二次多项式回归模型。结果表明：枯草芽孢杆菌发酵玉米秸秆产腐植酸的最佳条件为玉米秸秆与麸皮配比0.95∶1、尿素添加量0.81%、培养基初始pH 6.1，在37℃条件下发酵7 d，发酵产物腐植酸含量为19.58%，较优化前腐植酸含量提高了38.3%。

关键词：腐植酸;玉米秸秆;枯草芽孢杆菌;响应面法;副产物综合利用

中图分类号：S 816.6 文献标志码：A 文章编号：0253-2301（2021）10-0047-05

DOI： 10.13651/j.cnki.fjnykj.2021.10.010

Optimization of Humic Acid Production from Corn Straw Fermented byBacillus Subtilis Based on Response Surface Methodology

CHEN Yong-qiang

（Fujian Main Station of Agricultural Product Processing and Promotion， Fuzhou， Fujian 350003， China）

Abstract： In order to explore the best conditions for humic acid production from corn straw fermented by Bacillus subtilis， the proportion of corn straw and bran， the additive amount of urea and the initial pH of culture medium were taken as the experimental factors， and the content of humic acid was taken as the index. The factor levels were selected according to the results of single factor experiment， and the method of Box-Benhnken experimental design was used to study the interaction of various factors and their effects on humic acid， thus to obtain the quadratic polynomial regression model. The results showed that the optimal conditions of humic acid production from corn straw fermented by Bacillus subtilis were as follows： the proportion of corn straw and bran was 0.95∶1， the additive amount of urea was 0.81%， and the initial pH of culture medium was 6.1. After 7 days of fermentation at 37℃， the humic acid content of the fermentation products was 19.58%， which was 38.3% higher than that before the optimization.

Key words： Humic acid; Corn straw; Bacillus subtilis; Response surface methodology; Comprehensive utilization of by-products

玉米是我國重要粮食作物，每年产生大量玉米秸秆，如何提高这一农业废弃物的综合利用水平，减少环境污染和资源浪费，实现变废为宝、化害为利，具有非常重要的意义[1-3]。利用农业废弃物生产生物腐植酸是农业资源化和功能化的一个重要渠道，生物腐植酸活性比天然腐植酸高，作为一种生长调节剂，在种养殖等领域具有广泛用途[4-9]。当前生物腐植酸的发酵方法仍以人工堆建自然发酵为主，存在产量低、产品质量不稳定等问题[10-12]。本研究对前期筛选获得的具有腐植酸发酵能力的枯草芽孢杆菌进行发酵条件研究，以期为玉米秸秆的综合利用探索渠道，为利用玉米秸秆生产腐植酸提供试验依据。

1 材料与方法

1.1 原料与菌株

玉米秸秆、麸皮采自龙海市白水镇，玉米秸秆烘干粉碎备用。……